PT-2026-33848 · 0Xjacky · Nginx-Ui

Published 2026-04-20 · Updated 2026-04-20 · CVE-2026-34403

Mitre

CVSS v4.0

6.9

Medium

AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.5, all WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page. Version 2.3.5 patches the issue.

Fix

Weakness Enumeration

CWE-1385

Related Identifiers

CVE-2026-34403

Affected Products

Nginx-Ui

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-34403 · Security Note
• https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj · Note
• https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5 · Note